When landscapers are maintaining what’s already there — pruning, trimming or mowing the lawn — the city doesn’t have to pay prevailing wages. When they’re adding something new — planting a streetscape or building a new entrance to a park — then the city does.

And in Winnebago County in 2013, that means paying $29.58 an hour.

Tree plantings fall into both categories.

If landscapers are replacing a dead tree — whether it is being cut down because of the emerald ash borer or has been struck by lighting — then they are not protected by prevailing wages. If it’s a new tree that raises the value of the land, then they are protected.

Here’s Rockford’s dilemma: The city has started a new tree planting program, but it’s in response to the emerald ash borer. The invasive insect is expected to kill 5,000 ash trees over the next five years. The city intends to plant 1,000 new trees a year to replace the ones that will get cut down.

But the new trees will not necessarily be planted in the same spots as the old trees. Some of the trees coming down, planted in previous generations, interfere with wires or nearby sidewalks. Some of them are bundled with too many of one tree species leaving them vulnerable to the spread of disease or insects. And to save money, the city will plant the new trees in front of homes and yards throughout Rockford with the understanding that homeowners will water and care for them early on.

“It depends on the extent of what they’re doing,” Hofer said. “The bottom line is if you are improving the nature of the property with landscaping, you have to pay the prevailing wage.”

Rockford officials have taken that to mean the program falls under prevailing wage laws and will pay the $29.58 an hour.

The city had already bid out the work, which was being done in the $15 to $16 an hour range. But Rockford will now have to pay $60,000 more a year in labor costs, said street and forestry superintendent Mark Stockman.

Aldermen have not been asked to increase the amount currently set aside for the annual tree plantings — $280,000. That amount will only cover the cost of planting 800 trees a year under the higher wage rate, instead of planting 1,000 trees each year as originally planned.

The 20 percent cut shows the “extreme damage” that the state is doing in the wake of the ash borer, said Ald. Venita Hervey, D-5.

“I want people to receive a fair wage but this is reprehensible,” Hervey said. “We will now get far less for the same amount of money.”

But the prevailing wages serve good purpose and some communities require them when they’re not mandated by state law, Hofer said.

“They make it clear the city wants the best employees not the cheapest,” she said.